我正在处理另一个directshow图表，似乎无法理解我所看到的问题。当我在graphhedit中将图形组合在一起时它会显示:
filesource -> demux -> decoder -> color converter -> dmo -> external render
这工作完美，回放是惊人的!
但是在代码中(和图形构建完美没有错误)…它不能做我想要的……相反，它播放文件，但播放非常像素化和黑暗，它看起来像是跳过了前一帧的顶部，从未删除前一帧。
下面是我的代码:
private static void BuildGraph(IGraphBuilder pGraph, string source)
{
int hr = 0;
// Graph builder.
pBuilder = (ICaptureGraphBuilder2)new CaptureGraphBuilder2();
hr = pBuilder.SetFiltergraph(pGraph);
CheckHR(hr, "Can't SetFiltergraph.");
// Add File Source (Async.).
pFileSourceAsync = (IBaseFilter)new AsyncReader();
hr = pGraph.AddFilter(pFileSourceAsync, "File Source (Async.)");
CheckHR(hr, "Can't add File Source (Async.) to graph.");
// Set source filename.
pFileSourceAsync_src = pFileSourceAsync as IFileSourceFilter;
if (pFileSourceAsync_src == null)
{
CheckHR(unchecked((int)0x80004002), "Can't get IFileSourceFilter.");
}
hr = pFileSourceAsync_src.Load(source, null);
CheckHR(hr, "Can't load file.");
// Add MPEG4 Demultiplexor.
pMPEG4Demultiplexor = (IBaseFilter)Activator.CreateInstance(Type.GetTypeFromCLSID(CLSID_MPEG4Demultiplexor));
hr = pGraph.AddFilter(pMPEG4Demultiplexor, "MPEG4 Demultiplexor");
CheckHR(hr, "Can't add MPEG4 Demultiplexor to graph.");
// Add Microsoft DTV-DVD Video Decoder.
pMicrosoftDTVDVDVideoDecoder = (IBaseFilter)Activator.CreateInstance(Type.GetTypeFromCLSID(CLSID_MicrosoftDTVDVDVideoDecoder));
hr = pGraph.AddFilter(pMicrosoftDTVDVDVideoDecoder, "Microsoft DTV-DVD Video Decoder");
CheckHR(hr, "Can't add Microsoft DTV-DVD Video Decoder to graph.");
// Add Color Converter DMO.
dmoFilter = (IBaseFilter)new DMOWrapperFilter();
dmoWrapper = (IDMOWrapperFilter)dmoFilter;
hr = dmoWrapper.Init(CLSID_ColorConverterDMO, DMOCategory.VideoEffect);
CheckHR(hr, "Can't initialize Color Converter DMO.");
hr = pGraph.AddFilter(dmoFilter, "DMO Filter");
CheckHR(hr, "Can't add Color Converter DMO to graph.");
//IMediaParams dmoParams = dmoFilter as IMediaParams;
//MPData srcLeft = new MPData();
//MPData srcTop = new MPData();
//MPData destLeft = new MPData();
//MPData destTop = new MPData();
//MPData width = new MPData();
//MPData height = new MPData();
//srcLeft.vFloat = 0;
//srcTop.vFloat = 0;
//destLeft.vFloat = 0;
//destTop.vFloat = 0;
//width.vFloat = 1280;
//height.vFloat = 720;
//dmoParams.SetParam(0, srcLeft);
//dmoParams.SetParam(1, srcTop);
//dmoParams.SetParam(2, destLeft);
//dmoParams.SetParam(3, destTop);
//dmoParams.SetParam(4, width);
//dmoParams.SetParam(5, height);
// Add Smart Tee.
pSmartTee = (IBaseFilter)new SmartTee();
hr = pGraph.AddFilter(pSmartTee, "Smart Tee");
CheckHR(hr, "Can't add Smart Tee to graph.");
// Add Decklink Video Render.
pDecklinkVideoRender = CreateFilterByName(@"Decklink Video Render", CLSID_ExternalRenderers);
hr = pGraph.AddFilter(pDecklinkVideoRender, "Decklink Video Render");
CheckHR(hr, "Can't add Decklink Video Render to graph.");
// Add AVI Decompressor.
pAVIDecompressor = (IBaseFilter)new AVIDec();
hr = pGraph.AddFilter(pAVIDecompressor, "AVI Decompressor");
CheckHR(hr, "Can't add AVI Decompressor to graph.");
// Add Color Space Converter.
pColorSpaceConverter = (IBaseFilter)new Colour();
hr = pGraph.AddFilter(pColorSpaceConverter, "Color Space Converter");
CheckHR(hr, "Can't add Color Space Converter to graph.");
// Add Null Renderer.
pNullRenderer = (IBaseFilter)Activator.CreateInstance(Type.GetTypeFromCLSID(CLSID_NullRenderer));
hr = pGraph.AddFilter(pNullRenderer, "Null Renderer");
CheckHR(hr, "Can't add Null Renderer to graph.");
// Connect File Source (Async.) and MPEG4 Demultiplexor.
hr = pGraph.ConnectDirect(GetPin(pFileSourceAsync, "Output"), GetPin(pMPEG4Demultiplexor, "Input"), null);
CheckHR(hr, "Can't connect File Source (Async.) and MPEG4 Demultiplexor.");
// Connect MPEG4 Demultiplexor and Microsoft DTV-DVD Video Decoder.
hr = pGraph.ConnectDirect(GetPin(pMPEG4Demultiplexor, "Video 1"), GetPin(pMicrosoftDTVDVDVideoDecoder, "Video Input"), null);
CheckHR(hr, "Can't connect MPEG4 Demultiplexor and Microsoft DTV-DVD Video Decoder.");
// Connect Microsoft DTV-DVD Video Decoder and Color Converter DMO.
hr = pGraph.ConnectDirect(GetPin(pMicrosoftDTVDVDVideoDecoder, "Video Output 1"), GetPin(dmoFilter, "in0"), null);
CheckHR(hr, "Can't connect Microsoft DTV-DVD Video Decoder and Color Converter DMO.");
// Connect Color Converter DMO and Smart Tee Filter.
hr = pGraph.ConnectDirect(GetPin(dmoFilter, "out0"), GetPin(pSmartTee, "Input"), null);
CheckHR(hr, "Can't connect Color Converter DMO and Smart Tee Filter.");
// Connect Smart Tee Filter and Decklink Video Render.
hr = pGraph.ConnectDirect(GetPin(pSmartTee, "Capture"), GetPin(pDecklinkVideoRender, "In"), null);
CheckHR(hr, "Can't connect Smart Tee Filter and Decklink Video Render.");
// Add SampleGrabber.
pSampleGrabber = (IBaseFilter)Activator.CreateInstance(Type.GetTypeFromCLSID(CLSID_SampleGrabber));
hr = pGraph.AddFilter(pSampleGrabber, "SampleGrabber");
CheckHR(hr, "Can't add SampleGrabber to graph.");
(pSampleGrabber as ISampleGrabber).SetBufferSamples(true);
(pSampleGrabber as ISampleGrabber).SetOneShot(false);
// Connect Smart Tee and SampleGrabber.
hr = pGraph.ConnectDirect(GetPin(pSmartTee, "Preview"), GetPin(pSampleGrabber, "Input"), null);
CheckHR(hr, "Can't connect Smart Tee and SampleGrabber.");
// Connect SampleGrabber and AVIDecompressor.
hr = pGraph.ConnectDirect(GetPin(pSampleGrabber, "Output"), GetPin(pAVIDecompressor, "XForm In"), null);
CheckHR(hr, "Can't connect SampleGrabber and AVIDecompressor.");
// Connect AVIDecompressor and Color Space Converter.
hr = pGraph.ConnectDirect(GetPin(pAVIDecompressor, "XForm Out"), GetPin(pColorSpaceConverter, "Input"), null);
CheckHR(hr, "Can't connect Color Space Converter and SampleGrabber.");
// Connect Color Space Converter and Null Renderer.
hr = pGraph.ConnectDirect(GetPin(pColorSpaceConverter, "XForm Out"), GetPin(pNullRenderer, "In"), null);
CheckHR(hr, "Can't connect Color Space Converter and Null Renderer.");
// Set SampleGrabber Media Type.
AMMediaType pSampleGrabber_pmt = new AMMediaType();
pSampleGrabber_pmt.majorType = MediaType.Video;
pSampleGrabber_pmt.subType = MediaSubType.RGB32;
pSampleGrabber_pmt.formatType = FormatType.VideoInfo;
VideoInfoHeader pSampleGrabber_format = new VideoInfoHeader();
pSampleGrabber_pmt.formatPtr = Marshal.AllocCoTaskMem(Marshal.SizeOf(pSampleGrabber_format));
Marshal.StructureToPtr(pSampleGrabber_format, pSampleGrabber_pmt.formatPtr, false);
hr = ((ISampleGrabber)pSampleGrabber).SetMediaType(pSampleGrabber_pmt);
DsUtils.FreeAMMediaType(pSampleGrabber_pmt);
CheckHR(hr, "Can't set media type to sample grabber.");
}
你会看到我有更多的代码，如连接智能tee和样本抓取器(这不是原因，因为我之前已经注释了它，以检查结果和没有变化，最终我想从视频流抓取静止图像…所以当我准备好了的时候，我就把它放好了。
我认为问题是与颜色转换器dmo，但我不完全确定…确切的图形在graphhedit运行没有任何问题，但代码模式给了我可怕的回放。也许我忘了用dmo的颜色转换器做些什么?还是包装纸?如有任何意见，不胜感激。
谢谢,欢呼。
我没有关于Color Converter DMO的详细信息，但从其他Vista+ DMOs的经验来看-它们不打算在DirectShow中使用。是的，它们仍然是dmo，实现了IMediaObject接口，DMO Wrapper Filter也在那里，但一些小问题正在破坏集成。
如果它不能开箱即用，很可能您将不得不将DMO放入您自己的包装器过滤器中。这肯定是可行的，而且——好消息——它并没有那么复杂。
旧的dmo肯定是在DirectShow中使用股票包装过滤器进行测试的，这就是为什么它们一直在工作，这就是为什么DMO Wrapper Filter在第一位置可用的原因。